JPH02247057A - Instrument for detecting injecting condition of spray nozzle - Google Patents

Abstract

PURPOSE:To quickly detect abnormal working of a cooling water nozzle by arranging an injecting flow detecting plate for cooling water facing to the spray nozzle for cooling a continuous cast slab and utilizing a sensor fitted at the rear thereof in secondary cooling zone in continuous casting apparatus. CONSTITUTION:At the time of cooling the continuous cast slab produced with the continuous casting apparatus with the cooling water injected from plural spray nozzles at the secondary cooling zone, in order to prevent the continuous cast slab from being brought to deterioration of the quality with imbalanced cooling of the continuous cast slab caused by clogging with some foreign matter into a part of the nozzles, the detecting plate 2 having the face at the right angle to injecting flow S of the cooling water is arranged in front of plural spray nozzles 1 for cooling water. This detecting plate 2 is fixed to a measuring capsule 4 through a sound proof plate 5, and at the rear thereof, the sound detecting sensor 3 is fitted. A sound pulse caused by collision of the cooling water from the nozzle 1, is detected with the sensor 3 and the outputted signal is processed with a waveform processing device 6, and number and position of the nozzles clogged by the foreign matter in plural nozzles are quickly decided with a deciding device 7 and the abnormal condition of the nozzles is displayed on a display device 8, and the clogged nozzle is repaired to uniformly cool the continuous cast slab.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a device for accurately grasping the spraying state of a cooling spray nozzle, and in particular to a device for accurately grasping the spraying state of a cooling spray nozzle, and in particular to a device for accurately grasping the spraying state of a cooling spray nozzle. The present invention relates to a spray nozzle spray state detection device that is highly effective in detecting the spray state.

BACKGROUND ART Cooling of a slab in the secondary cooling zone of a continuous casting machine greatly affects not only the surface quality of the slab but also its internal quality, so it is necessary to homogenize the cooling effect.

Therefore, in the secondary cooling zone of a continuous casting machine, a spray nozzle that reaches several hundred to several thousand sides per strand is used.

However, these nozzles are easily clogged by foreign objects in the cooling water, and in order to ensure uniform cooling of the slab, it is important to prevent nozzle clogging as much as possible. It is necessary to accurately understand the situation and determine whether each nozzle is abnormal or normal.

Conventionally, the commonly used method for this determination is to inject cooling water from a spray nozzle during non-operation.
This is a method of visually observing this and determining whether the injection condition is good or bad.

However, this method has the disadvantage that there are problems in terms of worker safety, the judgment must be subjective, and the observer is required to have a high degree of skill.
Roughly, a large number of rolls are placed at the spray nozzle location to guide the slab, which not only makes work difficult, but also requires a great deal of effort to observe and judge the spray conditions of the dozens of spray nozzles. This was time consuming and was one of the factors that hindered productivity improvement in continuous casting equipment.

Therefore, various devices have been proposed that are capable of detecting the jetting state of a nozzle and determining its quality.

For example, in Japanese Patent Application Laid-open No. 50-202959, a pressure gauge and a flow meter are disposed in the middle of a supply pipe connected to a nozzle, and the detected values are used to detect a blocked nozzle using a predetermined calculation formula. A device configured to calculate numbers has been disclosed, and Japanese Patent Application Laid-open No. 61-249562 has a see-through window facing the jet stream from the nozzle. An apparatus has been disclosed that images the cloudy part that occurs and determines the injection state based on the image transfer result.

However, the former method can only determine the number of nozzles in a blocked state, and it is difficult to determine an abnormal injection state due to, for example, a nozzle head falling off, and it is not possible to identify a blocked nozzle. This identification has to be carried out by other means, such as, which has the drawback of requiring a great deal of time and effort.

In addition, when this device is applied to determine the injection state of spray nozzles installed in continuous casting equipment, since there are an extremely large number of such nozzles installed, blockage of some of these nozzles may cause the detected values of the pressure gauge and flow meter to vary. The changes that occur are so slight that the above-mentioned discrimination is difficult.

However, this problem can be solved by installing a pressure meter and a flow meter for each nozzle or every few nozzles, but this requires a large number of pressure gauges and flow meters, and it is difficult to control the accuracy of these meters. The configuration of the processing system that processes these detection results has become more complex than ever before, making it impractical.

On the other hand, when the latter is used to determine the jetting state of spray nozzles in continuous casting equipment, it is possible to determine the jetting state of each nozzle by using a cylinder with a see-through window and a built-in imaging device, and it is possible to identify blocked nozzles. You can also do it.

However, in the case of this device, the appearance of the cloudy part that occurs on the window surface changes depending on the facing state of the viewing window and the jet flow, so it is necessary to maintain the cylindrical body in a constant position with respect to the jet flow at all times. However, it is impossible to maintain this posture, especially in curved continuous casting equipment, and there is a drawback that accurate evaluation of the injection state is difficult.

In addition, in recent years, spray nozzles have been adopted that eject cooling water in a mist to uniformize the distribution of cooling water on the surface of the slab and improve the cooling condition. Since no cloudy areas were generated, it was difficult to determine whether the jetting condition was good or not based on the image transfer results.

Furthermore, since imaging is performed while moving the cylinder, there is a limit to reducing the time required to detect the injection state even if the moving speed is increased, which is a factor that hinders productivity improvement. .

Problems to be Solved by the Invention In view of the actual situation described above, the present invention is capable of individually and quickly detecting the injection state of a large number of nozzles, and can roughly determine the type of injection flow, injection amount, etc. The present invention attempts to propose a nozzle jetting state detection device that can accurately determine whether the jetting state is good or bad regardless of the conditions.

Means for Solving the Problems A nozzle injection state detection device according to the present invention comprises a jet flow detection plate disposed opposite to a nozzle, an acoustic detection sensor attached to the other surface of the detection plate, and a sound detection sensor attached to the other surface of the acoustic detection sensor. A device comprising: a signal processing device that processes an output signal; a measurement capsule that houses the detection plate, the acoustic detection sensor, and the signal processing device; and means for determining the injection state of the nozzle based on the acoustic output signal after the signal processing. By disposing an acoustic insulation plate between the detection plate and the measurement capsule, and fixing the detection plate and the acoustic insulation plate, and the acoustic insulation plate and the measurement capsule, respectively, the detection plate and the measurement capsule are acoustically isolated. The main point is that the structure is insulated.

In addition, as the determination means, a method is used in which a value related to the jetting state of the nozzle is determined from the output signal of the acoustic detection sensor, and this is compared with the same value obtained in advance after a proper jetting state. be able to.

Function: The jet stream from the spray nozzle collides with the detection plate placed opposite to the nozzle, and the sound generated inside the detection plate due to this collision is captured by the acoustic detection sensor attached to the other side, and is emitted by the piezoelectric effect. Based on the output signal generated by the sensor, the ejection state of the nozzle is recognized, and a judgment is made as to whether the nozzle is good or bad.

The output signal of the acoustic detection sensor is processed by a waveform processing device including a preamplifier, a main amplifier, a bandpass filter, a waveform processing section, and the like.

Vibroacoustic noise that cannot be removed by the bandpass filter alone is blocked by the acoustic insulating plate interposed between the detection plate and the measurement capsule, making it possible to accurately determine whether the spray nozzle is clogged.

As an acoustic insulation means, a detection plate and an acoustic insulation plate are fixed,
The reason for using a means for fixing the acoustic insulating plate and the measurement capsule is that if the detection plate, the acoustic insulating plate, and the measurement capsule are fixed integrally, the acoustic insulating effect becomes extremely small.

Embodiment FIG. 1 is a schematic block diagram showing an example of the configuration of the apparatus of the present invention, FIG. 2 is a block diagram showing an example of the configuration of a waveform processing device in the same device, and FIGS. 3 and 4 are spray diagrams in the same device. FIG. 3 is an explanatory diagram showing the positional relationship between the nozzle and the detection plate. FIG. 3 shows the spray nozzle and the detection plate viewed from the side, and FIG. 4 shows the spray nozzle and the detection plate viewed from the top.

In FIG. 1, (1) is a spray nozzle whose spray state is to be detected, (2) is a detection plate that is arranged opposite to each other within the reach of the jet flow ejected from the spray nozzle (1), (3) is the acoustic detection sensor attached to the other side of the detection plate (2), (4) is the measurement capsule, (5) is the acoustic insulation plate, and (6) is the output signal from the acoustic detection sensor (3). (7) is a determination device that determines the signal after the waveform processing; and (8) is a display device that displays the determination results. be.

The detection plate (2) is made of a material whose material, thickness, size, etc. are selected according to the properties of the jet S, such as the distribution width of the jet S, spray nozzle arrangement, etc. S
It is located at right angles to.

This detection plate (2) is connected to the acoustic insulation plate (
5), and the acoustic insulating plate (5) is fixed to the measurement capsule (4) with a nut (12). That is, acoustic insulation is provided to prevent the vibration sound of the measurement capsule (4) from propagating to the detection plate (2). As the acoustic insulating plate, for example, rubber of about H350 to H100 is suitable, but cork or the like can also be used.

The acoustic detection sensor (3) is generally an AE (Acoust
icEmission) sensor, which detects acoustic pulses in the high frequency range that occur in objects due to external stress, converts them into electrical signals corresponding to the size of the acoustic pulses using the piezoelectric effect, and outputs the signals. It is housed in a cylindrical sensor holder (3-1) and fixed to the detection plate (2) together with the holder.

In addition, in order to improve the adhesion of the acoustic detection sensor (3) to the detection plate (2), the holder (3-1) and the sensor (3)
) It is also possible to have a structure in which an elastic member such as a spring is interposed between the sensor and the sensor.

Also, the acoustic detection sensor (3) may be directly attached by adhesive or other means without using a sensor holder, but the detection accuracy of the sensor depends on the detection surface and detection plate (2). When fixing these, it is preferable to interpose grease or machine oil between them.

The waveform processing device (6) that processes the output signal of the acoustic detection sensor (3) includes a preamplifier (6-1), a main amplifier (
6-2), a bandpass filter (6-3), a waveform processing section (6-4), and the like. Since the output signal of the sensor is usually a weak signal of about 10 μV to 10 mV, it is amplified to a processable level by a preamplifier (6-1) and a main amplifier (6-2), and then passed through a bandpass filter (6-3). Only a predetermined frequency band is extracted and input to a determination device (7) that determines whether the injection condition is good or bad.

In order to suppress the attenuation of the output signal of the acoustic detection sensor (3) and eliminate the influence of electrical noise superimposed on the signal on the detection results, the preamplifier (6-1) is placed close to the acoustic detection sensor (3). In that case, it may be built into the sensor body, or it may be provided within the sensor holder.

In addition, preamplifier (6-1), main amplifier (6-2)
, there is no problem even if the processing order of the bandpass filter (6-3) is different.

To show the waveform processing device (6) more specifically, as shown in FIG.
), is amplified by the main amplifier (6-3), rectified by the waveform processing section (6-4), and then subjected to envelope detection.

The signal output from the waveform processing unit (6-4) is taken into the determination device (7) and compared with the spray output value of a normal nozzle, and if it is determined to be abnormal, it is displayed as abnormal on the display device (8). It is now possible to do so.

Note that the size and arrangement of the detection plate (2) will be determined depending on the arrangement of the nozzles for each measurement target.
As shown in the drawings and FIG. 4, it is preferable that the size of the detection plate (2) is a size that can be used to determine whether the spray is being handled or not, and that the detection plate (2) is arranged in a one-to-one correspondence with the nozzle (1).

When the injection state detection device configured as described above is used to detect the injection state of the spray nozzle in the secondary cooling zone of continuous casting equipment, the detection plate (2) is used together with the acoustic detection sensor (3) to detect the injection flow from the spray nozzle. It is necessary to move it while facing the

As a means for this, for example, at the start of casting, a plurality of recesses are formed on the side surface of the dummy bar, corresponding to the installation positions of the spray nozzles on the plane, and an acoustic detection sensor (3) is placed in each of these recesses. By fixing the detection plate (2) so that the installation side is inside and blocking the recess, the dummy bar can be moved with the detection plate (2) facing the jet stream from the spray nozzle. It is possible to configure it so that it is moved according to the situation.

In this case, when the dummy bar is introduced or handled as a bow, the jet stream from the spray nozzles arranged in parallel in the direction of movement of the dummy bar will successively collide with the surface of each detection plate (2). The acoustic detection sensor (3)
will detect acoustic pulses generated inside the detection plate (3) due to these collisions.

The measurement capsule (4) is attached to a dummy bar or the like and moves within the roll cavity during measurement. At this time, the vibration sound generated by the movement of the capsule is detected by an acoustic detection sensor (
3) will pick it up. Most of this vibration sound is removed by the band pass filter (6-3), but since the vibration itself is large, if the acoustic insulating plate (5) is not provided, it will become a large noise as shown in FIG. 5.

However, since the device of this invention performs acoustic insulation using an acoustic insulation plate (5), it is possible to significantly suppress the vibration noise compared to a case without an acoustic insulation plate, and it is possible to move the measurement capsule (4). This enables measurement with reduced vibration effects even when the sensor is in use, making it possible to determine nozzle clogging with good accuracy.

Fig. 6 is a diagram showing the temporal change in the output signal of the acoustic detection sensor when an acoustic insulating plate is used. This is an example of the output when the amount has not reached the predetermined amount, and when such a signal is given to the determination device (7), the nozzle is determined to be abnormal and displayed as abnormal on the display device (8). .

As described in detail, this inventive device has the following effects.

■ A detection plate placed opposite to the nozzle and an acoustic detection sensor attached to the detection plate - 1 Just includes an acoustic insulating plate interposed between the detection plate and the measurement capsule, and a simple waveform processing circuit to process the signal from the detection sensor. With this simple device configuration, the spray conditions of various spray nozzles can be detected with high accuracy, and the quality of the nozzles can be accurately determined.

■ By moving the detection plate by an appropriate means, the spraying status of multiple nozzles can be quickly detected.When applied to detecting the spraying status of spray nozzles in continuous casting equipment, the detection plate can be used as a dummy bar. By fixing it,
Since the injection state can be detected when the dummy bar is inserted or handled, there is no need to stop operation, and productivity can be greatly improved.

■ Even if vibration noise that cannot be removed by a band-pass filter alone is generated due to the movement of the measurement capsule attached to the dummy bar of the continuous casting machine, this vibration noise can be completely eliminated by the acoustic insulating plate interposed between the detection plate and the measurement capsule. This allows accurate determination of spray nozzle clogging.

[Brief explanation of drawings]

FIG. 1 is a schematic block diagram showing an example of the configuration of a device according to the present invention, FIG. 2 is a block diagram showing an example of the configuration of a waveform processing device in the same device, and FIGS. 3 and 4 are spray nozzles and detection in the same device. These are explanatory diagrams showing the positional relationship of the plates. FIG. 3 shows the spray nozzle and the detection plate viewed from the side, and FIG. 4 shows the spray nozzle and the detection plate viewed from the plane. FIG. 5 is a diagram showing an example of the output signal of the acoustic detection sensor in the same device as described above without an acoustic insulating plate, and FIG. 6 is a diagram showing an example of the output signal of the acoustic detection sensor of the device of the present invention. 1...Spray nozzle 2...Detection plate 3...
・Acoustic detection sensor 4...Measurement capsule 5...
・Acoustic insulation board 6...Waveform processing device 7...
・Determination device 8...Display device applicant
Sumitomo Metal Industries Co., Ltd.

Claims (1)

[Claims] A jet flow detection plate disposed opposite to the nozzle, an acoustic detection sensor attached to the other surface of the detection plate, a signal processing device that processes an output signal of the acoustic detection sensor, the detection plate, the acoustic detection sensor, and signal processing. A spray nozzle jetting state detection device comprising a measuring capsule housing the device, and means for determining the jetting state of the nozzle based on the acoustic output signal after the signal processing, the device comprising: a measuring capsule housing the device; It is characterized by a structure in which the sensing plate and the measuring capsule are acoustically insulated by arranging insulating plates and fixing the sensing plate and the acoustic insulating plate, and the acoustic insulating plate and the measuring capsule, respectively. Spray nozzle injection status detection device.